JPH025964Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal transfer recording device that locally heats an ink layer formed on the surface of an ink carrier and transfers the molten ink onto recording paper.

A conventional thermal transfer recording apparatus of this kind will be explained with reference to FIG. A straightening roller 2 is brought into contact with pressure, and a thin wire 3 is tightly wound in a spiral around the outer peripheral surface of the straightening roller 2, and a heater 4 is arranged inside.

Reference numeral 5 denotes an ink reservoir provided at the contact portion between the ink transport body 1 and the correction roller 2, and the ink in this ink reservoir 5 is a heat-melting ink that is solid at room temperature and whose fluidity increases when heated. It is heated and melted by the heater 4.

Reference numeral 6 denotes an ink layer formed on the surface of the ink carrier 1, and this ink layer 6 is obtained as follows. That is, when the ink transport body 1 is rotated in the direction of arrow a by a motor (not shown), the correction roller 2 in contact with the ink transport body 1 rotates in the direction of arrow b, and the outer peripheral surface of this correction roller 2 is rotated. The molten ink in the ink reservoir 5 passes through a generally triangular cavity continuous in the axial direction formed by the ink transport body 1 and the adjacent wire rods 3 wound around the ink reservoir 5 . Most of the ink that has passed through it adheres to the surface of the ink conveying body 1 whose temperature is lower than that of the correction roller 2, and this adhered ink becomes smooth and has a uniform thickness due to surface tension, and in the same way, it becomes continuous. An ink layer 6 is formed on the entire surface of the ink carrier 1. Note that the ink layer 6 thus formed
The ink is solidified by natural cooling or forced cooling by a fan (not shown) between the ink reservoir 5 and the thermal head 8.

7 is a recording paper; 8 is a thermal head provided so as to be in contact with the ink layer 6 through the recording paper 7; this thermal head 8 is placed on standby away from the recording paper 7 when not recording. It's summery.

A recording apparatus having such a configuration locally heats the ink layer 6 by feeding the recording paper 7 in the direction of the arrow c using a paper feeding mechanism (not shown) and selectively causing the heating element of the thermal head 8 to generate heat. The ink melted by heating is transferred to the recording paper 7 as dots, and by repeating this operation, characters etc. are recorded on the recording paper 7 using ink dots. When recording is performed in this manner, a recess is formed in the ink layer 6 due to the transfer of ink, but this recess is caused by the frictional force with the recording paper 7 sent in the direction of the arrow c, so that the ink transport body 1 moves in the direction of the arrow a.
By rotating in the direction, the ink is sent to the ink reservoir 5, where the ink is replenished, and at the same time, the smooth ink layer 6 is regenerated by the correction roller 2.

As explained above, in the conventional thermal transfer recording apparatus, ink in the ink layer transferred to the recording paper is replenished using an ink reservoir provided at the contact area between the ink conveying body and the correction roller. Because this ink reservoir can only store a small amount of ink due to its structure, the ink in the ink reservoir will completely run out when, for example, a few to 10 sheets of A4 paper are recorded. It was hot.
Therefore, an ink amount detector that detects the amount of ink in the ink reservoir and a means to appropriately replenish ink to the ink reservoir based on the signal from this detector are required, but it is extremely difficult to detect the presence or absence of a small amount of ink. Moreover, if an ink tank is provided separately and a mechanism for appropriately replenishing ink is provided, the apparatus becomes complicated, large-sized, and expensive.

Another disadvantage is that in order to be able to start recording after the power is turned on, the heat from the heater inside the straightening roller must be transmitted through the straightening roller to completely melt the ink in the ink reservoir, which requires a long start-up time. It was hot too.

The present invention is intended to solve these drawbacks, and aims to provide a thermal transfer recording device that has a short startup time, does not require an ink amount detector or an ink replenishment mechanism, and has a good ink layer regeneration function. do. To achieve this objective, the present invention forms an ink layer on the surface of a rotatable ink carrier using a heat-melting ink that is solid at room temperature and becomes fluid when heated, and the ink layer is formed on the surface of a rotatable ink carrier. In a thermal transfer recording device that locally heats the ink using a thermal head and thereby transfers the melted ink to the recording paper, the ink storage section has a width equivalent to that of the ink transport body and can store a large amount of ink, and the ink storage section An ink replenishment system that is integrally formed with an ink passage that protrudes laterally from the bottom of the ink passage, and a large number of fine grooves that are parallel to the moving direction of the ink transport body and are provided across the entire width of the ink passage on the lower surface of the ink passage. the ink replenisher is brought into pressure contact with the bottom end of the ink passage provided with the groove with the ink transport body so as to create a certain gap between the top end of the ink passage and the ink transport body. The pressure contact portion is located on the downstream side in the moving direction of the ink conveying body, the constant gap side is on the upstream side in the moving direction of the ink conveying body, and a heater is provided on at least one of the upper surface and the lower surface of the ink passage. It was established.

To explain the following with reference to the drawings, FIG. 2 is a side sectional view showing a first embodiment of the present invention, in which 1 is a roller-shaped ink conveying body, 6 is an ink layer formed on the surface of the ink conveying body 1, 7 is the recording paper, 8 is the recording paper 7
These thermal heads correspond to those shown in FIG.

Reference numeral 9 denotes an ink supply device, which has the same width as the ink transport body 1. This ink replenisher 9 is connected to the upper plate 10.
and a lower plate 11, the upper plate 10 and the lower plate 11
An ink accommodating portion 12 capable of accommodating a large amount of ink and an ink passage 13 protruding laterally from the bottom of the ink accommodating portion 12 are formed. The tip 10 of the upper plate 10 forming this ink passage 13
a is bent upward and the ink transport body 1
and are facing each other with a gap of about 1 mm.
Further, the tip 11a of the lower plate 11 is bent downward, and as shown in FIG. This groove 1 is provided in pitch.
4 is in pressure contact with the ink transport body 1 by a pressure contact means such as a spring (not shown).

In other words, the ink supply device 9 is connected to the tip 1 of the upper plate 10.
The tip of the lower plate 11a provided with the groove 14 is placed in pressure contact with the ink carrier so that a certain gap is formed between the ink carrier 1 and the ink carrier 1,
Here, the pressure contact portion is defined as the downstream side in the moving direction of the ink conveying body 1 as indicated by arrow b, and the constant gap side is defined as the upstream side in the moving direction of the ink conveying body 1.

15 and 16 are heaters; one heater 15 is arranged in close contact with the upper surface of the ink passage 13, and the other heater 16 is arranged in close contact with the lower surface of the ink passage 13.

The ink layer 6 in this configuration is formed as follows. That is, when the ink conveying body 1 is rotated in the direction of arrow b by a motor (not shown), a minute cavity formed by the ink conveying body 1 and the groove 14 provided at the tip 11a of the lower plate 11 is formed. The ink melted by the heaters 15 and 16 passes through, and the passed ink adheres to the surface of the ink carrier 1 and forms an ink layer 6 with a smooth and uniform thickness due to surface tension. An ink layer 6 is formed on the entire surface of the ink carrier 1.

The ink layer 6 thus formed is cooled naturally or forcibly by a fan (not shown) until it reaches the position of the thermal head 8 from the tip 11a of the lower plate 11 to a solid state. become

Next, the operation of the above-described configuration will be explained. First, since the power of the apparatus is turned off when not recording, the heaters 15 and 16 do not generate heat, and therefore the heat-melting ink contained in the ink replenisher 9 is solidified.

Therefore, when the power of the apparatus is turned on for recording, the heaters 15 and 16 disposed closely above and below the ink passage 13 of the ink replenisher 9 generate heat, so that the ink in the ink passage 13 is efficiently used. It melts well and is ready to start recording in a very short time. At this time, a portion of the ink in the ink storage portion 12 is also heated, and the surface layer of the ink in contact with the upper plate 10 and the lower plate 11 is in a melted state.

After this, the recording paper 7 is sent in the direction of arrow c by a paper feeding mechanism (not shown), and the heating element of the thermal head 8 is selectively heated to locally heat the ink layer 6, thereby melting the ink. is transferred as dots onto the recording paper 7, and by repeating this operation, characters, etc., are recorded on the recording paper 7 using ink dots.

This recording creates recesses in the ink layer 6 due to the transfer of ink, but these recesses are formed by the rotation of the ink carrier 1 in the direction of arrow b due to the frictional force with the recording paper 7 sent in the direction of arrow c. Replenisher 9
The ink is sent to the tip of the ink passage 13, where the ink is replenished, and at the same time, the smooth ink layer 6 is regenerated by the tip 11a of the lower plate 11.

In this way, the ink in the ink passage 13 is sequentially replenished to the ink layer 6 during recording, so as recording continues, the ink in the ink passage 13 gradually decreases.
Since the ink in the ink passage 2 is melted by the heat of the heaters 15 and 16, the ink that has been reduced is sequentially replenished into the ink passage 13.

In addition, in the embodiment described above, the ink passage 13
The narrower the gap in the vertical direction, the better the thermal response, but if it is too narrow, it will be difficult to maintain the gap in the width direction, so about 0.5 to 2 mm is appropriate.

Further, the length of the ink passage 13 is desirably 20 mm or more in order to ensure that the ink supplied from the ink storage section 12 to the ink passage 13 is sufficiently diffused in the width direction to prevent local ink shortages. .

Furthermore, the ink supply device 9 must be installed at an angle so that the ink flows smoothly from the ink storage section 12 to the ink passage 13, but if this angle is too large, the tip 10 of the upper plate 10
Ink will overflow from the gap between a and the ink carrier 1. However, if the angle is at least a predetermined angle, the ink will not overflow due to the rotation of the ink transport body 1 and the surface tension of the ink.

As explained above, in the first embodiment, an ink replenisher including an ink accommodating portion capable of accommodating a large amount of ink and an ink passage protruding laterally from the bottom of the ink accommodating portion is used to replenish the ink. The tip of the ink passage of the container is pressed into contact with the ink transport body, and heaters are placed on the top and bottom of the ink passage, so that the ink in the ink passage is efficiently melted by the heater after the power is turned on, and the ink in the ink passage is melted in an extremely short time. You will be able to start recording soon, so
The effect is that the rise time can be significantly shortened compared to the conventional method.

Further, the ink replenisher includes an ink storage section that can store a large amount of ink as described above, and an ink passage that protrudes laterally from the bottom of the ink storage section and automatically replenishes ink to the ink layer of the ink transport body. Because of this structure, a good ink layer can always be reproduced and a large amount of recording can be performed. For example, set the size of the ink storage part to 2 cm.
x 2cm x 20cm (height x depth x width), the amount of ink that can be stored is 80g (the specific gravity of the ink is 1g/
cm ³ ), and if the thickness of the ink layer formed on the surface of the ink carrier is 10 μm, 0.6 g of ink is required to blacken the area of one A4 sheet, but ink in actual recording is consumption is 1/
Since it is less than 10, you can continue to record more than 1000 A4 sheets. Therefore, it is possible to perform a large amount of recording without the need for conventional ink amount detectors, ink replenishment mechanisms, etc., and this prevents the device from becoming more complicated and larger. At the same time, it can also be prevented from becoming expensive. In other words, it is possible to realize a thermal transfer recording device that is simple in structure, has an excellent ink layer regeneration function, and is small and inexpensive.

Next, a second embodiment of the present invention will be explained with reference to FIG. The first embodiment described above uses a roller-shaped ink transport body 1 to perform recording by heating the ink layer 6 from the back side of the recording paper 7 with the thermal head 8, but this second embodiment As shown in FIG. 4, an ink carrier 17 made of heat-resistant plastic film such as polyester or polyimide or a metal thin film such as stainless steel is used in the form of an endless belt, and this ink carrier 17 is moved between two rollers 18. , 19, and an ink replenisher 9 is arranged on one roller 18 side in the same manner as in the first embodiment. The thermal head 8 is arranged to heat the ink layer 6 on the front surface of the ink carrier 17 from the back side, and the platen 20 and the ink carrier 17 are arranged to face the thermal head 8. The recording paper 7 is made to pass between the two.

According to the second embodiment, the ink layer 6 can be heated from the back side of the ink transport body 17 by the thermal head 8 and the ink can be transferred to the recording paper 7. In addition to this effect, there is an advantage that there is no restriction on the thickness of the recording paper 7.

In the first and second embodiments described above, the heaters 15 and 16 are arranged on the upper and lower surfaces of the ink passage 13, but it is not necessary to provide two heaters, and it is possible to use only one of them. good.

As explained above, the present invention integrally forms an ink accommodating section that has the same width as the ink transport body and can accommodate a large amount of ink, and an ink passage that protrudes laterally from the bottom of the ink accommodating section. An ink replenisher, which has a large number of fine grooves parallel to the moving direction of the ink transport body across the entire width of the ink passage, is installed at a constant distance between the top end of the ink passage and the ink transport body. The tip of the lower surface of the ink passage provided with the groove is placed in pressure contact with the ink transport body so as to form a gap, and the pressure contact part is placed on the downstream side in the moving direction of the ink transport body, and the side with the certain gap is placed in pressure contact with the ink transport body. Since the heater is provided on the upstream side in the moving direction of the conveyance body and on at least one of the upper surface and the lower surface of the ink passage, the following effects can be obtained.

First, since the ink accommodating portion and the ink passage are integrally formed, an ink replenisher with a simple structure and a small size can be realized.

In addition, since the bottom end of the ink passage provided with the groove is in pressure contact with the ink transport body so that a certain gap is created between the top end of the ink passage and the ink transport body, The amount of ink supplied is limited by the groove, and the amount of ink supplied to the ink transport body can be reliably regulated to a constant amount, and an ink layer with a constant and uniform thickness can be easily formed.
Can be played.

In addition, since the heater is placed on at least one of the upper and lower surfaces of the ink passage, the ink in the ink passage can be intensively heated when the power is turned on, and once only the ink in the ink passage has melted, it can be applied. Since recording can be started, the start-up time can be shortened.

In addition, since the ink passage protrudes sideways from the bottom of the ink accommodating part, the ink in the ink accommodating part melts from the surface layer that comes into contact with the melter and is sequentially replenished into the ink passage. The ink in the ink accommodating portion can be efficiently used to the last without providing a heater or heater.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view showing a conventional example, Fig. 2 is a side sectional view showing a first embodiment of the present invention, Fig. 3 is a partially enlarged perspective view of an ink supply device used in the present invention, and Fig. 4. FIG. 2 is a side sectional view showing a second embodiment of the present invention. 1... Ink carrier, 6... Ink layer, 7...
Recording paper, 8...Thermal head, 9...Ink supply device, 10...Top plate, 10a...Tip, 11...
Lower plate, 11a... Tip part, 12... Ink storage part,
13... Ink passage, 14... Groove, 15, 16...
...Heater, 17...Ink transport body.

Claims (1)

[Claim for Utility Model Registration] An ink layer is formed on the surface of a rotatable ink carrier using a heat-melting ink that is solid at room temperature and becomes fluid when heated, and the ink layer is transferred to a thermal head. In a thermal transfer recording device that locally heats the ink and thereby transfers the melted ink to the recording paper, the ink storage section has the same width as the ink transport body and can accommodate a large amount of ink, and the ink storage section An ink replenisher is integrally formed with an ink passage projecting laterally from the bottom, and a large number of fine grooves are provided across the entire width in the lower surface of the ink passage parallel to the moving direction of the ink transport body. and the ink replenisher is arranged such that the bottom end of the ink passage provided with the groove is in pressure contact with the ink transport body so that a certain gap is created between the top end of the ink passage and the ink transport body. At the same time, the pressure contact portion is located on the downstream side in the direction of movement of the ink transport body, the certain gap side is located on the upstream side in the direction of movement of the ink transport body, and a heater is provided on at least one of the upper surface or the lower surface of the ink passage. A thermal transfer recording device characterized by: